The present invention relates to amplifiers and, in particular, to amplifiers wherein nonlinearities of an output transducer coupled to the amplifier are controlled and compensated. More particularly, the present invention relates to an amplifier arrangement having a control circuit fed by a servo mechanism disposed on the output transducer coupled to the amplifier, thereby controlling and correcting nonlinearities in the response generated by the transducer. For example, the present invention has particular application to the control of nonlinearities generated by loudspeakers coupled to audio amplifiers.
Current audio reproduction is achieved through a system of amplification and reproduction in which the amplifier increases both voltage and current levels, while a transducer produces acoustic output by conversion of electrical energy into acoustic energy. Often the transducer, i.e., a loudspeaker, does not follow its input in linear fashion, resulting in phase, frequency, amplitude and harmonic distortion. Presently, no commercially available amplifier system has been designed to cope with transducer nonlinearities extensively through detection and correction of these nonlinearities.